The present invention relates to the field of computer networks. More specifically, the present invention relates to a method and apparatus for parallel trunking of interfaces to increase transfer bandwidth between network devices.
Local Area Networks (LANs) following the IEEE 802 Standard Architecture are network environments that interconnect end-nodes using various types of network elements. Each of these network elements is subject to its own set of configuration and topology guidelines. These sets of guidelines and rules are intended to deliver a uniform and well defined data link layer behavior over which upper network layers can operate. Examples of this behavior include the emulation of loop-free broadcast domains where any node may communicate with any other node with no prior signaling required, where packet ordering is preserved between any pair of end-nodes, and where every packet is delivered to its destination no more than once.
FIG. 1 illustrates a plurality of end-nodes interconnected by a network. End-nodes 110-113 are typically computers capable of sourcing packets to be delivered over the network 120 to other end-nodes. The end-nodes 110-113 are also capable of sinking packets sent to them by other end-nodes in the network 120. Routers are also considered end-nodes for the purposes of this description. Typical network elements used to build LANs are repeaters (hubs) and bridges. In some cases bridges are designated as LAN switches. The IEEE 802.1d Standard for transparent bridges (LAN switches) and IEEE 802.3 Standard for repeaters and end-nodes provide the topological rules that allow the data link layer behavior described.
Any one of the end-nodes 110-113 may send packets to any other end-node connected to the network 120. Packets are delivered at most once per destination. A sequence of packets sourced at one of the end-nodes 110-113 is seen in the same order at a destination end-node connected to the network 120.
FIG. 2 illustrates a network implementation. The network 200 includes a plurality of repeaters 210 and 211 and switches 220-222. As a rule, links or interfaces connected to repeaters have the same nominal speed or bit rate and links or interfaces connected to switches can have dissimilar speeds or bit rates. An additional property of the switches 220-222 is traffic isolation. Traffic isolation consists of forwarding packets of data only through the links or interfaces where the destination may reside. This property was deliberately defined to increase the overall network capacity. In order to accomplish traffic isolation, switches 220-222 must know which end-nodes 230-236 are reachable via each link or interface. Bridges or switches complying with IEEE 802.1d automatically learn this information with no assistance from the end-nodes 230-236 or any other external agent, and are called transparent bridges.
FIG. 3 illustrates a transparent bridge. Bridge 310 is connected to end-nodes 311-313. A packet from end-node 311 to end-node 312 is not sent to the link where end-node 313 resides because of the property of traffic isolation. The bridge 310 learns the location of the end-nodes 311-313.
Network capacity is central to the function of a network. Traditionally, there have been two approaches to increasing network capacity. The first approach involves partitioning the network. The partitioning approach uses switches, bridges, and routers to replace a network of repeaters. By replacing the network of repeaters with more sophisticated hub devices, the flow of packets in the network is better managed and system performance is increased. The second approach involves providing faster link alternatives. By implementing links that can support higher bandwidth, the network capacity is increased.
Nevertheless, at any given point in time, the choice of link speeds (10, 100, 1000 Mbps) may not match up very well with the amount of sustained throughput that a particular device can support. When switches and high performance routers are used to interconnect multiple links of a given speed, there is a clear need for the inter-switch or inter-router link to be able to support at least some aggregation of the links. If new hardware is required to utilize a newer, higher speed, increased bandwidth network, the utilization of the newer network may not be as attractive from a cost standpoint. Furthermore, the cost associated with implementing a newer network with more sophisticated hubs or faster links may also not be attractive from a cost standpoint.
Thus, what is needed is a method and apparatus for increasing data transfer bandwidth between network devices, such as end-nodes and switches.
A method for interconnecting a first device and a second device in a network is described. The first device and the second device are connected to a plurality of interfaces. The plurality of interfaces emulate a single high-speed interface.
A method for creating a multiple interface connection is disclosed. A first identifier is assigned to a first interface and a second interface at the first device. A path between the first device to the second device is identified with the first identifier.
A second method for creating a multi-interface connection is disclosed. A first device is connected to a plurality of interfaces. The plurality of interfaces emulate a single high-speed interface.
A network is disclosed. The network includes a first device and a second device. A first interface is coupled to the first device and the second device. A second interface is coupled to the first device and the second device. The first interface and the second interface emulate a single high speed interface. According to an embodiment of the present invention, the first interface and the second interface are assigned an identifier that identifies a path between the first device and the second device.
A network device is disclosed. The network device includes a first port that is connected to a first interface. The network also includes a second port that is connected to a second interface. A trunking pseudo driver is coupled to the first port and the second port. The trunking pseudo driver allows the first interface and second interface to emulate a single high-speed device.